1. Field of the Invention
Embodiments of the invention relate to the field of computer systems, and more specifically, to display cards.
2. Description of Related Art
Peripheral Component Interconnect (PCI) Express Base has become increasingly popular in modern computer systems. The PCI Express Base is well suited for use in traditional personal computer (PC), laptop, notebook, mobile computers, and server architectures. Advantages of PCI Express architecture include low pin count, high speed, serial device-to-device interconnect. Therefore, for platforms using PCI Express, there is a need for new graphics capabilities. There is, however, no mechanism to make use of a digital display codec using the PCI Express connector. In a typical platform using the PCI Express, the Accelerated Graphics Port (AGP) model is no longer applicable.
Existing techniques to solve the above problem are inadequate. One technique is to place the display codec on the motherboard. This technique is expensive because the motherboards may have to include unnecessary circuitry or space for platforms that do not need a digital display. Furthermore, it creates many significant placement and routing issues in the motherboard design. Another technique is to provide the digital display codec device on the PCI Express card. However, this technique is not desirable because of the incompatibility between the clocking and transfer rates of the PCI Express and the digital codec device. The PCI Express is defined as a fixed frequency interface that requires significant amounts of logic and bandwidth overhead to handle building and decoding packets while digital displays need to have variable clocking and transfer rates and need very little overhead for the transfer of video data.